Hss pro tin coated drill bit 2 1.0mm ol34mm wl12mm irwin 10502596, the irwin hss pro tin drill bits are primarily designed for drilling metal and harder, tougher alloys'. '.strtoupper('c')ompared to traditional hss twist drill bits, speed can be increased by 40 60% and feed by 10 20% without reducing the life time of the drill bit significantly'. '.strtoupper('t')in is also a poor conductor of heat, so the heat generated during the drilling process is diverted into the chips and coolant and less into the drill bit'. '.strtoupper('t')hese drills have a 135deg split point grinding tip which ensures perfect centring and reduced drilling pressure'. '.strtoupper('t')he drill bit body is manufactured from high quality hss steel coated with 2.5micro titanium nitride tin, the tin coating has a hardness of app'. '.strtoupper('8')0 hrc and is very resistant to wear'. '.strtoupper('t')in has a low coefficient of friction, this results in less power being consumed and less heat generated during the drilling.irwin hss pro tin coated drill bit'. '.strtoupper('s')ize 8.5 x 117mm'. '.strtoupper('i')rwin® 10502596 hss pro tin coated drill bit 8.5mm ol117mm wl75mm